Diaphragm pumps



Jan. 9, 1968 c. QUATREDENIERS ETAL 3,362,341

D IAPHRAGM PUMPS Filed Oct. 11, 1965 2 Sheets-Sheet 1 Inventors C /Qade' Qzzafredenz'ers 5 2 72a 220:?05

United States Patent 47,4 4 1 Claim. 01. 103-150 ABSTRACT OF THE DISCLOSURE A liquid fuel pump of the diaphragm type in which a sheet metal pump head encloses a flexible portion separating inlet and outlet passages of the head.

This invention relates to diaphragm pumps and in particular to diaphragm pumps such as are commonly used as fuel pumps for internal combustion engines.

A diaphragm pump according to the invention has a flexible diaphragm the periphery of which is pressed into sealing engagement with a seat in a pump body by means of a valve and seat plate assembly, shaped from sheet material, the periphery of which is pressed into sealing contact with the diaphragm by a periphery flange of a pressed sheet metal cover which is crimped over the pump body adjacent the seat therein.

The valve and seat plate assembly comprises a valve seat plate with inlet and outlet valve ports controlled by movable valve members which are engageable with valve seats on the plate; and a separately formed sleeve, which may be of resilient material, extends around one of said valves, preferably the inlet valve, and is secured at opposite ends between said cover and said seat plate to divide the space therebetween into an inlet and an outlet chamber.

The pump cover preferably has an opening therein which is in communication with the inlet chamber, and a filter screen is preferably secured over said opening by means of a cap which is secured to the cover.

Conveniently the filter screen has a peripheral gasket and also a central gasket which is a sliding fit on a bolt which extends through the cap and said central gasket and is secured in a nut fixed 'to the pump cover so that the cap can be tightened into sealing contact with the cover, the peripheral gasket being clamped between the cap and cover.

Inlet and outlet connections are and cover respectively.

Reference will now be made to the accompanying informal drawings which illustrate a preferred embodiment of the invention and in which:

FIGURE 1 is a vertical section through a diaphragm pump according to the invention intended for use as a fuel pump for an internal combustion engine;

FIGURE 2 is a plan, partly in section, of FIGURE 1;

FIGURE 3 is a detail section of a modified valve construction;

FIGURE 4 is a detail section showing one method of sealing the cover to the body of the pump;

FIGURE 5 is a detail section showing another method of sealing the pump cover and body; and

FIGURE 6 is a detail section showing an alternative form of the sleeve which separates the pump inlet and outlet chambers.

The diaphragm pump shown in FIGURES 1 and 2 comprises a relatively rigid pump body 1 in the upper part of which is an annular seat 2 against which is pressed the peripheral portion of a flexible diaphragm 3, the periphery of the diaphragm being engaged by the periphprovided on said cap 3,362,341 Patented Jan. 9, 1968 eral portion of a valve and seat plate assembly 4 which in turn is engaged by the peripheral portion of a pump cover 5 which is pressed against the superimposed peripheral portions of the seat plate 4 and diaphragm 3 and is crimped over the pump body 1 adjacent the seat 2, as shown at 6 firmly to hold the sheet metal pump head on the rigid body 1.

The diaphragm 3 is clamped at its central portion between an upper and a lower plate 7, 8 which are secured on one end of a reciprocatory rod 9 the lower end of which carries an abutment 10 adapted to be engaged by one end 11 of a pivotal rocker arm 12 which is pivotally mounted on a spindle 14 secured in the pump body. The other end 15 of the rocker arm 12 is adapted to be engaged by a rotary cam 16 driven in known manner from a cam shaft of the engine on which the pump is to be mounted.

The rocker arm 12 is normally biased into engagement with the cam 16 by means of a compression spring 17 one end of which abuts a seat on the pump body and the other end of which engages the rocker arm 12.

The rod 9 extends through a guide plate 19 located in a seat 20 in the pump body; and one end of a spring 21 engages said guide plate and the other end engages under the plate 8 so as normally to press the diaphragm 3 up- Wards and engage the abutment 10 with the end 11 of the rocker arm 12.

The diaphragm 3 is preferably preformed with a plurality of annular corrugations therein and may be made from a fabric, such as cotton impregnated and covered on each side with a synthetic elastomeric material resistant to fuel and oil, or it may be made of a synthetic elastomeric material such as synthetic rubber.

The valve and seat assembly 4 comprises a seat plate,

preferably made as a sheet metal stamping, which has therein inlet openings 23 and outlet openings 24. A valve disc 25 overlies the inlet openings 23 and is pressed into engagement with a valve seat on the seat plate 4 by means of a coil spring 26 one end of which engages the valve disc and the other end of which engages under the head of a rivet 27 the end of which is riveted over onto the other side of the seat plate 4.

Similarly a valve disc 28 overlies the outlet openings 24 and is pressed into engagement with a valve seat on the seat plate 4 (on the opposite side thereof to the inlet valve disc) by means of a helical spring 29 one end of which engages the valve disc 28 and the other end of which engages under the head of a rivet 30 the end of which is riveted over onto the other side of the seat plate 4.

The portion of the seat plate 4 on which the inlet valve 25 is mounted is of inverted cup shape and forms a seat for one end of a sleeve 31, of resilient material such as rubber, the other end of which is engaged by the cover 5 so that the sleeve 31 is clamped between the cover 5 and the seat plate 4, the space within the sleeve constituting an inlet chamber which is separated by the sleeve 31 from the remainder of the space, constituting the outlet chamber of the pump, between the cover 5 and seat plate The cover 5 has therein an opening 32 overlying the inlet valve 23, 25; and a filter disc 33 overlies the opening 32 and is secured to the top of the cover 5 by means of a cap 34 which is secured to the cover 5 by a bolt 35 which engages in a nut 36 secured to the cover 5. The filter disc 33 has a peripheral gasket 37 which is clamped between the cap 34 and the cover 5 and also has a central gasket 38 which is a sealing fit over the bolt 35.

An inlet pipe 39 is secured in the cap 34 and an outlet pipe 40 is secured in the cover 5, the inlet and outlet pipes respectively communicating with the inlet and outlet chambers of the pump.

As shown in FIGURE 2, the pin 14 on which the rocker arm 11, 15 is mounted is located in a transverse bore in the body 1 of the pump, the ends of the bore being sealed by means of cups 41 which are pressed into opposite ends of the bore and form a sealing fit therein so as to prevent the escape of oil around the pin 14.

As shown in FIGURE 4, an annular gasket 50 of plastics or other sealing material may be interposed between the crimped-over peripheral portion of the pump cover 5 and the periphery of the valve and seat plate 4 to form a seal therebetween; or as shown in FIGURE 5, an annular step 52 maybe formed in the peripheral portion of the cover 5 to form a seat for the peripheral portion of the valve and seat plate 4, the cover 5 being sealed 7 t the body 1, as in the construction shown in FIGURES 1 and 4, by the peripheral portion of the diaphragm 3 which is clamped between the cover and body 1.

As shown in FIGURE 6, the flexible sleeve 31 may be replaced by a metal sleeve 131, one end of which is welded, as shown at 132, to the cover 5 and the other end of which is press-fitted over the cup-shaped portion of the seat plate 4 in which the valve 23, 25 is mounted.

The fuel pump constructions described above have the advantage that the cap, the cover and the valve and seat plate assembly can all be made from sheet metal as pressings or stampings and can be readily assembled and secured on the pump body, the arrangement permitting reduced cost and simplification of manufacture. The employment of a flexible sleeve 31 to form the pump inlet chamber also contributes to the simplicity of manufacture and assembly of the pump.

We claim:

1. A pump having a pump head of sheet metal enclosing inlet and outlet valves serving inlet and outlet passages respectively, said pump head being fixed to a rigid pump body with the periphery of a pumping diaphragm interposed, a valve seat plate positioned between said pump head and said diaphragm, a unitary and separately formed sleeve of resilient, flexible and rubber-like material surrounding one of said valves, one end of said unitary sleeve being held in fluid tight relation with said sheet metal .and the other end being held in fluid tight relation with said seat plate to separate said inlet and outlet passages.

References Cited UNITED STATES PATENTS 2,022,660 12/1935 Flint 103-150 2,117,863 5/1938 Slekely 230- 2,969,745 1/1961 Johnson et al 103228 3,150,601 9/1964 Smith et al. 103223 3,236,383 2/1966 Smith et a1. 210136 3,278,032 11/1966 Smith 103150 FOREIGN PATENTS 915,548 1/1963 Great Britain. 1,306,702 9/1962 France. 1,209,217 9/1959 France.

DONLEY I. STOCKING, Primary Examiner.

ROBERT A. OLEARY, Examiner.

W. L. FREEH, Assistant Examiner. 

